Just to let people know, or maybe just a reminder for those that already know, you'll get better battery life if you use a background with a lot of black in it. The reason: OLED screens only turn on pixels that are colored, black areas remain off. This is why you get such great black from OLED screens, because the pixels are literally turned off, whereas on LED screens all the pixels are backlit, which makes black areas appear more of a gray.